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Case Studies – Converting the Ignitor setup on a 90 DSM Turbo to a 91.

A friend of mine recently picked up a 90 Eclipse Turbo for 400 dollars in non running condition. After a few minutes, we determine that the engine lacks spark and after a few tests, we find that the ignitor is completely dead.

As the 90 is the “black sheep” of the DSM family, I elect to rewire his 90 to a 91 ignitor setup to get him back on the road.

the dead unit is on the left, we are converting to the 1991 ignitor on the right

Parts you will need to perform this swap :

x1 1991 Eclipse / Talon / Laser Ignitor plus harness / wiring loom

x1 1991 Eclipse / Talon / Laser instrument cluster.

Tools : Soldering Iron, Notepad, Solder, Flux.

A look at the new ignitor and flying loom

This conversion is fairly straightforward procedure, and can be installed by any average mechanic.

Now we take a look at the small markings on your stock J122 ignitor and compare them to the markings on the pinouts of the J722T Ignitor.

Now we cut and solder the wires in corresponding order :
OC1—>OC1

IB1—>IB1G

IB2—->IB2G

OC2—>OC2

After cutting and resoldering the wires, we have VB, TACH wires left over.

Now, take the white wire from the coil plug on the ECU side, and solder it to the tach wire on the J722T Ignitor Plug. Then, we slice VB ( the black / white wire ) of the J722T Ignitor plug to the Black / White wire on the coil plug ( ECU Side )

Shown is the 1990 Tacho Interface, which isn’t needed now since we have eliminated and rewired it. Since the new ignitor now sends the tachometer signal to the new cluster, we no longer need the white wire, simply tape it up.

With the old ignitor and the tacho interface removed, the 90 fires right up and drives fine. However the tachometer doesn’t work as he needs a 91 instrument cluster to make it all work as it should.

Note : If you cannot source a 91 instrument cluster, you can simply swap the ECU pins 6 and 14 to complete the job.